Accessibility issues with Font Awesome

[roelvangils]

The Modal, Navigation and Datepicker component all use icons.

(not blocking)

Failures:

• Many of the icons don't have a text alternative (WCAG 4.1.2). See alt Decision Tree for more info.
• Images are not marked up as images. Refer to failure F87 for the failure and ARIA Technique 24 for a possible solution. Advisory: using self-hosted images is even more robust and lighter for the user.

This doesn't satisfy 1.1.1 Non-text Content, 1.3.1 Info and Relationships and 4.1.2 Name, Role, Value.

Note: this issue applies to all components that use Font Awesome icons.